[Emacs-diffs] trunk r116704: Fix more failures of visual-order cursor movement under word-wrap (bug#16961).

[Eli Zaretskii]

------------------------------------------------------------
revno: 116704
revision-id: address@hidden
parent: address@hidden
fixes bug: http://debbugs.gnu.org/16961
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Sat 2014-03-08 12:54:43 +0200
message:
  Fix more failures of visual-order cursor movement under word-wrap (bug#16961).
  
   src/xdisp.c (move_it_in_display_line_to): If word-wrap is ON, and
   there's a valid wrap point in the display line, the last glyph
   cannot "just barely fit" on this row, because display_line doesn't
   let it.  Instead, proceed as if the last glyph didn't fit, so that
   we eventually back up the iterator to the wrap point.  This avoids
   delusional behavior of move_it_to, whereby it proceeds to the next
   display line, but sets current_x to zero for all the glyphs that
   without word-wrap would fit on the previous display line.  One
   result was that visual-order cursor movement behaved erratically
   under word-wrap.
   (Fmove_point_visually): Add code to find the x coordinate of the
   last character before wrap point, under word-wrap on a TTY.
modified:
  src/ChangeLog                  changelog-20091113204419-o5vbwnq5f7feedwu-1438
  src/xdisp.c                    xdisp.c-20091113204419-o5vbwnq5f7feedwu-240

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2014-03-07 20:00:33 +0000
+++ b/src/ChangeLog     2014-03-08 10:54:43 +0000
@@ -1,3 +1,18 @@
+2014-03-08  Eli Zaretskii  <address@hidden>
+
+       * xdisp.c (move_it_in_display_line_to): If word-wrap is ON, and
+       there's a valid wrap point in the display line, the last glyph
+       cannot "just barely fit" on this row, because display_line doesn't
+       let it.  Instead, proceed as if the last glyph didn't fit, so that
+       we eventually back up the iterator to the wrap point.  This avoids
+       delusional behavior of move_it_to, whereby it proceeds to the next
+       display line, but sets current_x to zero for all the glyphs that
+       without word-wrap would fit on the previous display line.  One
+       result was that visual-order cursor movement behaved erratically
+       under word-wrap.
+       (Fmove_point_visually): Add code to find the x coordinate of the
+       last character before wrap point, under word-wrap on a TTY.
+
 2014-03-07  Eli Zaretskii  <address@hidden>
 
        * xdisp.c (Fmove_point_visually): When under word-wrap, accept

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2014-03-07 20:00:33 +0000
+++ b/src/xdisp.c       2014-03-08 10:54:43 +0000
@@ -8651,7 +8651,12 @@
                         doesn't fit on the line, e.g. a wide image.  */
                      it->hpos == 0
                      || (new_x == it->last_visible_x
-                         && FRAME_WINDOW_P (it->f)))
+                         && FRAME_WINDOW_P (it->f)
+                         /* When word-wrap is ON and we have a valid
+                            wrap point, we don't allow the last glyph
+                            to "just barely fit" on the line.  */
+                         && (it->line_wrap != WORD_WRAP
+                             || wrap_it.sp < 0)))
                    {
                      ++it->hpos;
                      it->current_x = new_x;
@@ -20857,6 +20862,27 @@
              move_it_by_lines (&it, -1);
              target_x = it.last_visible_x - !FRAME_WINDOW_P (it.f);
              target_is_eol_p = true;
+             /* Under word-wrap, we don't know the x coordinate of
+                the last character displayed on the previous line,
+                which immediately precedes the wrap point.  To find
+                out its x coordinate, we try moving to the right
+                margin of the window, which will stop at the wrap
+                point, and then reset target_x to point at the
+                character that precedes the wrap point.  This is not
+                needed on GUI frames, because (see below) there we
+                move from the left margin one grapheme cluster at a
+                time, and stop when we hit the wrap point.  */
+             if (!FRAME_WINDOW_P (it.f) && it.line_wrap == WORD_WRAP)
+               {
+                 void *it_data = NULL;
+                 struct it it2;
+
+                 SAVE_IT (it2, it, it_data);
+                 move_it_in_display_line_to (&it, ZV, target_x,
+                                             MOVE_TO_POS | MOVE_TO_X);
+                 target_x = it.current_x - 1;
+                 RESTORE_IT (&it, &it2, it_data);
+               }
            }
        }
       else